LixadaSolar Panel Charger USB Port Portable High Power Paper Shaped Monocrystalline Silicon 10W Solar Panel Charger for Cell Phone Camping Riding Climbing Travel Outdoor Activity

My first one broke after three months use in the backcountry, but I'm still giving five stars because this panel rocks!I strapped it to the top of my pack, angled slightly away from me on a north bound thru hike. This panel and a 5000MaH battery kept my phone fully charged all through the desert and above treeline, I only needed to supplement power when the weather was bad, or when I dipped into forested areas.It's small enough that I just put a second panel and battery on top of my pack later in my hike, this gave me more than enough power most days, and I eventually got rid of my wall charger all together.

Hooked this thing up to a Nitecore 10K power bank that was a little over 25% discharged. Kept in full sun here in southern California for 2 days and wondered why it was still charging. If it was a 10W solar panel it should be putting out 2 amps at 5 volts, which would be more than enough to charge even a 50% discharged 10K power bank in 2 days of full sun.So, I reordered from my first order to get another one to compare. Second one arrived, different dimensions, connector on different side, and it came with 2 caribiners, which the first one did not have. What the heck???Hooked both up, since the nitecore has 2 usb charge input/outputs. Verified that each panel was delivering power by checking each with the other disconnected. Day 3, things are still charging in full sun.A little research reveals that you can reasonably expect about 70 mW per square inch from a typical solar panel. Let's be charitable and say these panels can produce 100 mW per square inch. The first panel I got has some blank lines running through it and is slightly larger than the second panel, which has no lines. Measuring the cell areas: #1 measures 8.5 x 5 inches. #2 measures 8 x 5". Let's say they are both 8 x 5 since the bigger one loses some area with the lines. That's 40 square inches per panel. 100 mW/square inch x 40 square inches gives 4 Watts. So, being charitable these panels at best produce 4 watts. So it's frankly BS to call them 10 watt panels. Add in all the other inefficiencies of charging a power bank and then using the power bank to recharge a phone, for example, and you've got a really ineffective solution. Makes me really wonder about some of the reviews on here.

Attention AT hikers, if you want a panel to take with you on your hike, this is the one. First, the reason for the 3 out of 5 star rating. One simple reason, this is described as a 10 watt solar panel. It is not. The maximum I have recorded (out of multiple tests) was around 3.5 watts. This is a 5 watt panel, not a 10 watt panel, and that is being generous. That is the reason for the lower rating. If this company would change the description from 10 watt to 5 watt, I would give all 5 stars. As a 10 watt panel, it is 3 stars, but 5 star 5 watt panel. One last con is the usb port which others have covered. Supposedly it comes off easily when the panel gets hot because of the glue they use. I cannot vouch for this because as soon as I received it I put some superglue around the usb port, and no matter how hot the panel gets it's on there solidly. Now for all the pros, and there are many.First, this seems very well constructed. It is tough and very light.Second, the total weight for the panel, not including any charge cord, is an amazing 2 7/8 oz. Yep, under 3oz, and that's it and that's why I recommend for AT hikers. Ultralite. Even with me adding a little superglue around the usb port, it didn't affect the weight. Still 2 7/8 oz.Third, even though it only maxes out at 3.5 watts, that is plenty to keep your phone charged. By my estimation, 3.5 hours of full sun with this panel will completely charge my I phone. It can charge a 5000mah battery in 5.75 hours (enough to charge my phone 1.7 times) and a 10000mah battery in 11-12 hours. I recommend the battery. Don't charge your phone directly from the panel, because the charge fluctuates constantly and I wouldn't recommend that for a phone battery. Let a regular $10 5000mah battery take that beating and protect your phone battery.Fourth, the price. $20. Totally worth it for a 5 watt panel this well made.For hiking, I use this panel (82g, 2 7/8 oz), a 10,000mah battery (187g, 6 5/8oz), two braided 12" charge cords, one micro-usb and one apple for my iPhone (26g 7/8oz), and a wall plug adapter with usb port (36g, 1 1/4oz). Obviously the plug is for when I hit town and can charge my phone and battery up quickly. You will need the micro-usb cord to charge the battery from the panel, and also to charge most devices from the battery. I have an iPhone so I also need the apple charge cord. This makes a total of 331g, or 11.675oz. Not bad to keep your phone charged. I start out with a full charge, and the 10000mah battery holds 3 charges. With the panel I can be out for weeks and keep my phone going. If you want to go with the smaller 5000mah battery, that is 1.7 charges and knock of 3 oz from the total weight (8.675oz). If you have decent sun that would probably work too. I attach the panel to the back of my pack and put the battery in a pocket to protect it from the sun with the charge cord between them.To sum up, the only issues are the usb port (easily fixed) and listing this as a 10 watt panel when it can barely qualify as a 5 watt. Other than that, affordable, well constructed, tough and ultralite. I highly recommend this panel, especially for hikers watching their pack weight. My only recommendations are, use better glue on the usb port, and change description from 10 watt to 5 watt.